Add a "fork" of musl as //fusl.

fusl/src/crypt/crypt.c

Index: fusl/src/crypt/crypt.c
diff --git a/fusl/src/crypt/crypt.c b/fusl/src/crypt/crypt.c
new file mode 100644
index 0000000000000000000000000000000000000000..46500737b6598ae58f740ba2808e35507e2b73ba
--- /dev/null
+++ b/fusl/src/crypt/crypt.c
@@ -0,0 +1,16 @@
+#include <unistd.h>
+#include <crypt.h>
+
+char *__crypt_r(const char *, const char *, struct crypt_data *);
+
+char *crypt(const char *key, const char *salt)
+{
+	/* This buffer is sufficiently large for all
+	 * currently-supported hash types. It needs to be updated if
+	 * longer hashes are added. The cast to struct crypt_data * is
+	 * purely to meet the public API requirements of the crypt_r
+	 * function; the implementation of crypt_r uses the object
+	 * purely as a char buffer. */
+	static char buf[128];
+	return __crypt_r(key, salt, (struct crypt_data *)buf);
+}